Allyl quinaldinium pyridinium phosphates



United States Patent Ofiice 3,337,556 ALLYL QUINALDINIUM PYRIDINIUM PHOSPHATES Harry Kroll, Warwick, R.I., assignor to Sarki Research and Development Corporation, a corporation of Rhode Island No Drawing. Original application Mar. 18, 1963, Ser. No. 266,063, now Patent No. 3,170,854, dated Feb. 23, 1965. Divided and this application Apr. 24, 1964, Ser. No. 362,486

The portion of the term of the patent subsequent to Feb. 23, 1982, has been disclaimed Claims. (Cl. 260-286) This is a division of application Ser. No. 266,063, filed Mar. 18, 1963, now U.S. Patent 3,170,854.

This invention relates to a composition of organic phosphates useful for addition to electroplating baths, i.e. solutions of water-soluble nickel salts to improve the brightness of nickel electrodeposited from such solutions. The organic phosphate additives produce electrodeposits of nickel on base metals which are highly lustrous, adherent and ductile.

The subject compounds are nitrogen heterocyclic derivatives belonging to the pyridine, quinoline and isoquinoline groups which have been reacted with trialkyl phosphates to yield N-alkyl pyridinium, d-ialkyl phosphates, N-alkyl quinolinium dialkyl phosphates, and N-alkylisoquinolinium dialkyl phosphates. These compounds can be represented by the following:

R OP(O R), Pyridinlum compounds R an Isoquinolinium compounds In the above representations, R is an aliphatic group saturated or unsaturated, having from one to four carbon atoms, for example, methyl, ethyl, propyl, butyl, allyl and methallyl, R may be hydrogen, i.e., no substituent on the ring, or an aliphatic group of one or two carbon atoms, such as methyl, ethyl, or vinyl, and may be substituted in any position of the pyridine, quinoline, or isoquinoline ring or rings. Of outstanding utility are the N- allyl quinaldinium diallyl phosphate, N-allyl 2-vinyl-pyridinium diallyl phosphate, N-ethyl isoquinolininm diethyl phosphate, N-buty 4-vinyl pyridinium ditbutyl phosphate,

:and mixtures of the pyridinium and quinolinium and quinaldinium N-alkyl dialkyl phosphates. It should be noted that 2-methyl quinoline is quinaldine and the nomenclature herein reflects this in use of quinaldinium to identify the Z-methyl quinoline moiety.

The organic derivatives which are the basis of this inven-tion and the preferred concentrations at which they are used in electroplating baths are listed in Table 1. They are used jointly with the sulfur compounds described in Table 2. The sulfur compounds listed are a representative group useful for the purpose.

'Although quaternary ammonium salts of nitrogen heterocyclics have been previously identified as useful additives to bright nickel plating baths, dialkyl phosphate salts of the N-alkyl pyridinium, quinolinium, isoquinolinium and quinaldinium salts are unique for this application and are also unreported as compounds.

3,337,556 Patented Aug. 22, 1967 The current conventional practice in employing a quaternized nitrogen heterocyclic for a bright nickel plating bath is to choose a compound in which the anion is derived from a water soluble inorganic acid, such as chloride, bromide, sulfate, etc., which forms soluble nickel salts.

I have found that if the acid anion is a dialkyl ester of orthophosphoric acid ranging in molecular Weight from about 125 to 225, and if the nitrogen in the cation is quaternized with an alkyl group of the same chemical structure as the alkyl group in the dialkyl ortho phosphate anion, a product is obtained which is water dispersible and produces a superior brilliant adherent nickel deposit when added to a nickel electroplating bath containing the organic additives described in Table 2.

The use of the compounds in accordance With this invention for producing bright nickel deposits is based on electro-depositing nickel from a solution of one or more nickel salts to which there has been added 0.005 to 0.30 gram per liter of an N-alkylpyridinium, quinolinium, quinaldinium, or isoquinolininm dialkyl phosphate (see Table 1 herein) together with 0.1 to grams per liter of a water soluble sulfur compound in which the sulfur atom has a valence of +4 or +6, and is selected from the group of aliphatic unsaturated sulfonic acids, mononuclear and binuclear aromatic sulfonic acids, heterocyclic sulfonic acids, mononuclear aromatic sulfinic acids, aromatic sulfonamides and sulfonimides (see Table 2 herein). The water soluble alkali metal, ammonium, magnesium, and nickel salts of the above compounds are used in combination with the quaternary nitrogen cyclic compounds in accordance with this invention.

The brightener additives used in the method of this invention were evaluated in a Hull cell using a standard Watts type bath containing 330 grams of nickel sulfate hexahydrate/liter, 45 grams of nickel chloride per liter, 37.5 grams per liter of boric acid, operated at a pH of 3.5, and a temperature of 50 C. The nickel deposits were made on brass Hull cell panels 2" by 3" by plating for five minutes at three amperes. The concentrations and combination of organic additives which gave brilliant mirror-like deposits of nickel over a wide current density range are listed in Table 3.

Lustrous and adherent nickel deposits were also obtained from baths having the following composition:

Bath N0. 1

Grams/liter Nickel sulfate .6H O 330 Sodium chloride 30 N-allyl 2-vinyl pyridinium diallyl phosphate 0.01 Naphthalene trisulfonic acid 2.0 8.0

Bath N0. 2 Nickel fluoborate 225 Nickel chloride .6H O 30 Boric acid 30' N-allyl quinaldinium diallyl phosphate 0.005.l0 2,3 naphthalene disulfonic acid 2.0-8.0

The above plating compositions are illustrative of the ranges of bath compositions which have been tested successfully and do not indicate any limit of the bath composition which can be employed in accordance with the invention. Actually useful ranges of nickel concentration are from 200-400 grams per liter; whether the nickel be present as sulfate, chloride, nitrate or fluoborate.

The concentrations of the organic sulfur additives and the nitrogen heterocyclic additives listed in the tables are by no means limiting. Preferred operative ranges are given. A considerable variation in concentration of these agents is permissible depending on what the specifications require of the electrodeposited nickel; i.e. brightness, ductility, thickness, speed of build-up, etc.

It is also well understood in the process of bright nickel electroplating that in order to obtain pit-free nickel deposits, it is advantageous to employ agitated, well-filtered solutions. The use of a Wetting agent such as sodium lauryl sulfate at concentrations up to 0.25 gram per liter also permits the electroplating of pit-free nickel deposits.

The synthesis of these novel brighteners is readily carried out in accordance with the following procedure:

Example I.Allyl quinaldinium diallyl phosphate Reagents Mols Weight Weight m 3, 588 7 lbs., 14% oz.

Quinaldine 2,480 5 lbs., 8 oz.

Prcedure.The triallyl phosphate and quinaldine are mixed together, and carefully heated to 65 C. The temperature is allowed to rise slowly to 120 C. This is accomplished by shutting of the heating mantles at -10 degree intervals, and allowing the temperature to rise due to the exothermic contribution of the reactions. When the temperature reaches 120 C., and the exothermic phase of the reaction is completed, the temperature is raised at 130 C., and held at this point for twelve hours.

To determine the point of completion of the reaction, a 1 gram sample is removed and titrated potentiometrically using a glass-calomel electrode system, and an ethylene glycolisopropanol solvent system.

The pyridine compounds are synthesized in the same fashion. The trialkyl phosphate ester is reacted with the appropriate pyridine in stoichiometric proportions and the quaternized com-pound recovered. Thus trimethyl, triethyl, tripropyl, trib'utyl, triallyl or trimethallyl phosphate is reacted, as in Example 1, in a 1:1 molar ratio to make the corresponding quaternized compound.

Example II.To synthesize the methallyl quinaldinium dimethallyl phosphate, the trirnethallyl ester is reacted with quinoline under the conditions described in Example 1.

Example lII.To make the propyl quinaldinium dipropyl phosphate, the tripropyl phosphate is reacted with the quinoline as in Example I.

Example lV.Similarly, for making the methyl, ethyl and butyl compounds, the corresponding trialkyl phosphates are reacted with the quinoline.

In Table II, I have listed a group of preferred sulfur compounds which are commonly referred to in the trade as primary brighteners. By this, is meant that they are added to the plating bath as brighteners and with the cyclic nitrogen compounds give a net result which is a substantial improvement over the effect obtained with either one alone. The preferred concentration ranges are also indicated.

Any of the primary brighteners listed in Table 2 as being typical maybe combined with any of the secondary brighteners of Table I in the conventional acid vnickel plating baths. I have tested a large variety of combinations, virtually exhausting the possibilities, and have found that, in all cases, an improvement in the brightening effect is obtained. In Table III, I have listed certain of the preferred combinations, indicating that in any of the conventional Watts type baths used in the art, or conforming to those indicated herein, the combination will produce optimum results. Here, it will be noted that in some cases there are two sulfur compounds where pyridine, quinoline and isoquinoline components are used. In all cases, the results are characterized by the fact that improvements in brighteners, adherence, ductility are obtained under ordinary nickel plating conditions.

TABLE I Compound: Concentration range, grams/liter (1) N-allyl pyridinium diallyl phosphate 0.0=01.10 (2) N-Z-methallyl pyridinium dimethyl phosphate 0.00l.10 (3) N-pro-pyl Z-methyl pyridinium dipropyl phosphate 0.001-.10 (4) N-allyl 2-vinyl pyridinium diallyl phosphate 0.001-.10 (5) N-allyl 4-vinyl pyridinium diallyl phosphate 0.00l-.10 (6) N-allyl Z-methyl quinolinium diallyl phosphate 0.001-.10 (7) N-propyl 2-methyl quinolinium dipropyl phosphate 0.001-.10

(8) N-butyl quinolinium dibutyl phosphate 0.001-.l0 (9) N-methallyl quinolinium dimethallyl phosphate 0.001-.l0 (10) N-pr0pyl quinolinium dipropyl phosphate 0.001-10 (ll) N-allyl isoquinolinium diallyl phosphate 0.001-.10 (l2) N-rnethallyl isoquinolinium dimethallyl phosphate 0.001.10 (13) N-butyl isoquinolinium dibutyl phosv phate 0.001-.10 (14) N-propyl isoquinolinium dipropyl phosphate 0.00l-.10 (15) N-ethyl isoquinolinium diethyl phosphate 0.001-.10

TABLE II.-ORGA-NIC SULFUR ADDITIVES Bath No.Additin agents:

TABLE III Grams/ liter O-benzoyl sulfonimide Para toluenesulfonamide N-butyl Z-mefthylquinolinium dibutyl phosphate O-benzoyl sulfonimide N-Inetha1lyl quinolinium dimethallyl phosphate Benzenesulfonamide O-benzoylsulfonimide N-allyl 2-vinylpyridinium diallyl phosphate Benzene sulfonamide O-benzoylsulfonirnide N-allyl 4-vinyl pyridinium phosphate O-benzoylsulfonimide Para toluenesulfonamide N-ethyl isoquinolinium diethyl phosphate Para toluenesulfonarnide O-benzoyl sulfonimide N-propyl 2-viny1pyridinium dipropyl phosphate O-benzoyl sulfonimide N-allyl Z-methyl quinolinium diallyl phosphate Allyl sulfonic acid N-allyl Z-methylquinolinium diallyl phosphate Naphthalene trisulfonic acid (10) N-allyl Z-methylquinolinium diallyl phosphate Benzenesulfonate, sodium salt What is claimed is: 1. A compound having a formula given by a structure selected from the group consisting of:

wherein R is selected from the ethyl, propyl, butyl, allyl, and methallyl; R is selected from the group consisting of hydrogen, methyl, ethyl, and

vinyl, and n has a value of 0-1.

2. N-allyl quinaldini um diallyl phosphate.

3. N-allyl 2-vinyl pyridinium diallyl phosphate. 4. N-allyl 4-vinyl pyridinium diallyl phosphate. 5. N-allyl quinolinium diallyl phosphate.

References Cited UNITED STATES PATENTS ALEX MAZEL, Primary Examiner.

D. DAUS, Assistant Examiner. 

1. A COMPOUND HAVING A FORMULA GIVEN BY A STRUCTURE SELECTED FROM THE GROUP CONSISTING OF:
 2. N-ALLYL QUINALDINIUM DIALLYL PHOSPHATE. 